Comparison of collision test results for center-pillar reinforcements with TWB and CR420/CFRP hybrid composite materials using experimental and theoretical methods

In this study, vehicle center-pillar reinforcements were formed from steel tailor welded blanks (TWBs) and CR420 steel/carbon-fiber-reinforced plastic (CR420/CFRP) hybrid composite materials. After forming, collision tests were conducted to evaluate the fracture toughness of the center-pillar reinforcements made of TWB and of CR420/CFRP hybrid composite materials. The center-pillar reinforcement with the CR420/CFRP hybrid composite materials was lighter than the one with TWB, and the CR420/CFRP fracture toughness was also improved. The experimental collision results were compared with a computer-aided engineering simulation to provide a second verification. The detailed results were analyzed using the Abaqus/explicit software. Because the elastic modulus of the TWB is higher than that of the CR420/CFRP hybrid composite materials, the impact time for the CR420/CFRP hybrid composite materials is longer than for the TWB. Accordingly, when conducting the collision test of the CR420/CFRP hybrid composite materials, the impulse that the impactor received was greater. When the TWB was replaced with the next generation CR420/CFRP composite material, the body weight of the car became lighter by approximately 44%, while the impulse improved by approximately 10.0%. In this simulation, the impact time, fracture toughness and velocity change of the impactor were evaluated and were in close agreement with the experimental results.